The present invention relates to a motion sensor device. The present invention furthermore relates to the utilization of such a motion sensor device within a wall or ceiling light.
Motion detection sensors in the form of various detection technologies and corresponding technical principles are known from the prior art, wherein a common and frequent application is the use of such a motion detection sensor for activating a light. For example, it is common practice to utilize so-called PIR (passive infrared) sensors for the motion detection in interior and exterior regions (e.g. referred to a building, on which a corresponding motion sensor device is installed either by itself or in connection with a lighting unit) and to thereby control a lighting system, wherein these sensors generate a detection signal based on detected infrared radiation in the detection region (more precisely: infrared radiation in the map of the detection region, which changes due to the motion of an object to be detected) and activate a downstream consumer as a reaction thereto. However, devices of this type, which are based on the infrared principle, also have certain disadvantages; first of all, an effective detection region, i.e. a region defined by the maximum distance of a detection object with a certain minimum size to be reliably detected, is limited due to the principle used. In addition, infrared-based sensors can be affected by environmental influences such as, e.g., changes in the temperature and/or light conditions and therefore cause potentially undesirable false activations.
High-frequency or radar sensors are increasingly used as an alternative to the PIR sensor technology, particularly for controlling a lighting system, wherein such sensors operate based on a change of reflected and detected high-frequency waves and to this end typically utilize the Doppler principle, i.e. a frequency shift of the high-frequency signal, which is caused by a motion (or moving speed) of an object to be detected in the detection region and evaluated for the detection. However, this high-frequency technology is—due to the principle used—also associated with certain disadvantages; a detector sensitivity (and therefore also a motion detection sensitivity) is dependent on the (moving) direction, in which the detection object moves relative to the sensor. For example, an object motion in the direction toward the sensor or radially away from this sensor causes a completely different Doppler signal than an object moving tangentially in the detection region. In addition, the difference between a relatively small detection object moving in the vicinity of the sensor and a relatively large object moving at a greater distance from the sensor (and potentially even outside a desired detection region) is difficult to detect with such a sensor and therefore also creates problems. Furthermore, the ability of high-frequency signals to penetrate materials leads to undesirable properties of the motion sensor; the motion sensor may, if applicable, also react to motions that take place behind a wall or similar partition and are irrelevant to a detection function.
In order to overcome the disadvantages of high-frequency motion detector means, DE 10 2012 103 177 A1 of the applicant, which is considered as most closely related prior art, proposes to activate and evaluate two Doppler high-frequency detectors, which are spaced apart from one another, such that not only a simple Doppler signal can be obtained from a combined detector signal and evaluated for the motion detection, but an angle signal in the form of an instantaneous position angle of a detection object, as well as a distance signal in the form of an instantaneous distance of the detection object from an assigned sensor housing, can also be generated with this technology. In this case, it is possible to evaluate and specify, for example, a defined maximum distance of the detection object from the sensor housing from an evaluation of these obtained signals such that the motion sensor device can in this respect operate in a detection mode, which is insensitive to the above-described interfering influences, and has a precise and reproducible detection behavior.
However, the technology described in DE 10 2012 103 177 A1 is still in need of improvement with respect to its configurability and user-friendliness; for example, it is difficult for a user of such a known exterior sensor device to adjust or define a detection region in a plane of motion, which is not arcuate and radially symmetrical to the sensor housing as starting point for the sensor functionality. This means that the known technology is also not particularly well suited for use in the field of consumer goods, in which not only low manufacturing costs, but also a simple operation, preferably without the need for instructions or user manuals, can be a critical success factor.